1 /*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
5 * The main loop for the interactive session (client side).
6 *
7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
12 *
13 *
14 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 *
36 *
37 * SSH2 support added by Markus Friedl.
38 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
50 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
51 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
52 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
53 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
54 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
55 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
56 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
57 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
58 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
59 */
60
61 /*
62 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
63 */
64
65 #include "includes.h"
66 RCSID("$OpenBSD: clientloop.c,v 1.104 2002/08/22 19:38:42 stevesk Exp $");
67
68 #include "ssh.h"
69 #include "ssh1.h"
70 #include "ssh2.h"
71 #include "xmalloc.h"
72 #include "packet.h"
73 #include "buffer.h"
74 #include "compat.h"
75 #include "channels.h"
76 #include "dispatch.h"
77 #include "buffer.h"
78 #include "bufaux.h"
79 #include "key.h"
80 #include "kex.h"
81 #include "log.h"
82 #include "readconf.h"
83 #include "clientloop.h"
84 #include "authfd.h"
85 #include "atomicio.h"
86 #include "sshtty.h"
87 #include "misc.h"
88 #include "readpass.h"
89
90 /* import options */
91 extern Options options;
92
93 /* Flag indicating that stdin should be redirected from /dev/null. */
94 extern int stdin_null_flag;
95
96 /*
97 * Name of the host we are connecting to. This is the name given on the
98 * command line, or the HostName specified for the user-supplied name in a
99 * configuration file.
100 */
101 extern char *host;
102
103 /*
104 * Flag to indicate that we have received a window change signal which has
105 * not yet been processed. This will cause a message indicating the new
106 * window size to be sent to the server a little later. This is volatile
107 * because this is updated in a signal handler.
108 */
109 static volatile sig_atomic_t received_window_change_signal = 0;
110 static volatile sig_atomic_t received_signal = 0;
111
112 /* Flag indicating whether the user's terminal is in non-blocking mode. */
113 static int in_non_blocking_mode = 0;
114
115 /* Common data for the client loop code. */
116 static int quit_pending; /* Set to non-zero to quit the client loop. */
117 static int escape_char; /* Escape character. */
118 static int escape_pending; /* Last character was the escape character */
119 static int last_was_cr; /* Last character was a newline. */
120 static int exit_status; /* Used to store the exit status of the command. */
121 static int stdin_eof; /* EOF has been encountered on standard error. */
122 static Buffer stdin_buffer; /* Buffer for stdin data. */
123 static Buffer stdout_buffer; /* Buffer for stdout data. */
124 static Buffer stderr_buffer; /* Buffer for stderr data. */
125 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
126 static u_int buffer_high; /* Soft max buffer size. */
127 static int connection_in; /* Connection to server (input). */
128 static int connection_out; /* Connection to server (output). */
129 static int need_rekeying; /* Set to non-zero if rekeying is requested. */
130 static int session_closed = 0; /* In SSH2: login session closed. */
131 static int server_alive_timeouts = 0; /* Number of outstanding alive packets. */
132
133 static void client_init_dispatch(void);
134 int session_ident = -1;
135
136 /*XXX*/
137 extern Kex *xxx_kex;
138
139 extern int will_daemonize;
140
141 /* Restores stdin to blocking mode. */
142
143 static void
leave_non_blocking(void)144 leave_non_blocking(void)
145 {
146 if (in_non_blocking_mode) {
147 (void) fcntl(fileno(stdin), F_SETFL, 0);
148 in_non_blocking_mode = 0;
149 fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
150 }
151 }
152
153 /* Puts stdin terminal in non-blocking mode. */
154
155 static void
enter_non_blocking(void)156 enter_non_blocking(void)
157 {
158 in_non_blocking_mode = 1;
159 (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
160 fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
161 }
162
163 /*
164 * Signal handler for the window change signal (SIGWINCH). This just sets a
165 * flag indicating that the window has changed.
166 */
167
168 static void
window_change_handler(int sig)169 window_change_handler(int sig)
170 {
171 received_window_change_signal = 1;
172 signal(SIGWINCH, window_change_handler);
173 }
174
175 /*
176 * Signal handler for signals that cause the program to terminate. These
177 * signals must be trapped to restore terminal modes.
178 */
179
180 static void
signal_handler(int sig)181 signal_handler(int sig)
182 {
183 received_signal = sig;
184 quit_pending = 1;
185 }
186
187 /*
188 * Returns current time in seconds from Jan 1, 1970 with the maximum
189 * available resolution.
190 */
191
192 static double
get_current_time(void)193 get_current_time(void)
194 {
195 struct timeval tv;
196 gettimeofday(&tv, NULL);
197 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
198 }
199
200 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
201 void
client_x11_get_proto(const char * display,const char * xauth_path,u_int trusted,char ** _proto,char ** _data)202 client_x11_get_proto(const char *display, const char *xauth_path,
203 u_int trusted, char **_proto, char **_data)
204 {
205 char cmd[1024];
206 char line[512];
207 char xdisplay[512];
208 static char proto[512], data[512];
209 FILE *f;
210 int got_data = 0, generated = 0, do_unlink = 0, i;
211 char *xauthdir, *xauthfile;
212 struct stat st;
213
214 xauthdir = xauthfile = NULL;
215 *_proto = proto;
216 *_data = data;
217 proto[0] = data[0] = '\0';
218
219 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
220 debug("No xauth program.");
221 } else {
222 if (display == NULL) {
223 debug("x11_get_proto: DISPLAY not set");
224 return;
225 }
226 /*
227 * Handle FamilyLocal case where $DISPLAY does
228 * not match an authorization entry. For this we
229 * just try "xauth list unix:displaynum.screennum".
230 * XXX: "localhost" match to determine FamilyLocal
231 * is not perfect.
232 */
233 if (strncmp(display, "localhost:", 10) == 0) {
234 snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
235 display + 10);
236 display = xdisplay;
237 }
238 if (trusted == 0) {
239 xauthdir = xmalloc(MAXPATHLEN);
240 xauthfile = xmalloc(MAXPATHLEN);
241 strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
242 if (mkdtemp(xauthdir) != NULL) {
243 do_unlink = 1;
244 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
245 xauthdir);
246 snprintf(cmd, sizeof(cmd),
247 "%s -f %s generate %s " SSH_X11_PROTO
248 " untrusted timeout 1200 2>" _PATH_DEVNULL,
249 xauth_path, xauthfile, display);
250 debug2("x11_get_proto: %s", cmd);
251 if (system(cmd) == 0)
252 generated = 1;
253 }
254 }
255
256 /*
257 * When in untrusted mode, we read the cookie only if it was
258 * successfully generated as an untrusted one in the step
259 * above.
260 */
261 if (trusted || generated) {
262 snprintf(cmd, sizeof(cmd),
263 "%s %s%s list %s 2>" _PATH_DEVNULL,
264 xauth_path,
265 generated ? "-f " : "" ,
266 generated ? xauthfile : "",
267 display);
268 debug2("x11_get_proto: %s", cmd);
269 f = popen(cmd, "r");
270 if (f && fgets(line, sizeof(line), f) &&
271 sscanf(line, "%*s %511s %511s", proto, data) == 2)
272 got_data = 1;
273 if (f)
274 pclose(f);
275 }
276 else
277 error("Warning: untrusted X11 forwarding setup failed: "
278 "xauth key data not generated");
279 }
280
281 if (do_unlink) {
282 unlink(xauthfile);
283 rmdir(xauthdir);
284 }
285 if (xauthdir)
286 xfree(xauthdir);
287 if (xauthfile)
288 xfree(xauthfile);
289
290 /*
291 * If we didn't get authentication data, just make up some
292 * data. The forwarding code will check the validity of the
293 * response anyway, and substitute this data. The X11
294 * server, however, will ignore this fake data and use
295 * whatever authentication mechanisms it was using otherwise
296 * for the local connection.
297 */
298 if (!got_data) {
299 u_int32_t rnd = 0;
300
301 log("Warning: No xauth data; "
302 "using fake authentication data for X11 forwarding.");
303 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
304 for (i = 0; i < 16; i++) {
305 if (i % 4 == 0)
306 rnd = arc4random();
307 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
308 rnd & 0xff);
309 rnd >>= 8;
310 }
311 }
312 }
313
314 /*
315 * This is called when the interactive is entered. This checks if there is
316 * an EOF coming on stdin. We must check this explicitly, as select() does
317 * not appear to wake up when redirecting from /dev/null.
318 */
319
320 static void
client_check_initial_eof_on_stdin(void)321 client_check_initial_eof_on_stdin(void)
322 {
323 int len;
324 char buf[1];
325
326 /*
327 * If standard input is to be "redirected from /dev/null", we simply
328 * mark that we have seen an EOF and send an EOF message to the
329 * server. Otherwise, we try to read a single character; it appears
330 * that for some files, such /dev/null, select() never wakes up for
331 * read for this descriptor, which means that we never get EOF. This
332 * way we will get the EOF if stdin comes from /dev/null or similar.
333 */
334 if (stdin_null_flag) {
335 /* Fake EOF on stdin. */
336 debug("Sending eof.");
337 stdin_eof = 1;
338 packet_start(SSH_CMSG_EOF);
339 packet_send();
340 } else {
341 enter_non_blocking();
342
343 /* Check for immediate EOF on stdin. */
344 len = read(fileno(stdin), buf, 1);
345 if (len == 0) {
346 /* EOF. Record that we have seen it and send EOF to server. */
347 debug("Sending eof.");
348 stdin_eof = 1;
349 packet_start(SSH_CMSG_EOF);
350 packet_send();
351 } else if (len > 0) {
352 /*
353 * Got data. We must store the data in the buffer,
354 * and also process it as an escape character if
355 * appropriate.
356 */
357 if ((u_char) buf[0] == escape_char)
358 escape_pending = 1;
359 else
360 buffer_append(&stdin_buffer, buf, 1);
361 }
362 leave_non_blocking();
363 }
364 }
365
366
367 /*
368 * Make packets from buffered stdin data, and buffer them for sending to the
369 * connection.
370 */
371
372 static void
client_make_packets_from_stdin_data(void)373 client_make_packets_from_stdin_data(void)
374 {
375 u_int len;
376
377 /* Send buffered stdin data to the server. */
378 while (buffer_len(&stdin_buffer) > 0 &&
379 packet_not_very_much_data_to_write()) {
380 len = buffer_len(&stdin_buffer);
381 /* Keep the packets at reasonable size. */
382 if (len > packet_get_maxsize())
383 len = packet_get_maxsize();
384 packet_start(SSH_CMSG_STDIN_DATA);
385 packet_put_string(buffer_ptr(&stdin_buffer), len);
386 packet_send();
387 buffer_consume(&stdin_buffer, len);
388 stdin_bytes += len;
389 /* If we have a pending EOF, send it now. */
390 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
391 packet_start(SSH_CMSG_EOF);
392 packet_send();
393 }
394 }
395 }
396
397 /*
398 * Checks if the client window has changed, and sends a packet about it to
399 * the server if so. The actual change is detected elsewhere (by a software
400 * interrupt on Unix); this just checks the flag and sends a message if
401 * appropriate.
402 */
403
404 static void
client_check_window_change(void)405 client_check_window_change(void)
406 {
407 struct winsize ws;
408 Channel *c;
409
410 if (! received_window_change_signal)
411 return;
412
413 /*
414 * We want to send a window-change request only when a session is
415 * already established and alive.
416 *
417 * Note: During session handshake we cannot send window-change request,
418 * because we do not know the remote channel ID yet. We have to store
419 * the information about signals which have arrived and send the
420 * window-change request when the channel and the session are fully
421 * established.
422 */
423 if (compat20) {
424 if (session_ident == -1 || session_closed)
425 return;
426 c = channel_lookup(session_ident);
427 if (c == NULL || c->type != SSH_CHANNEL_OPEN ||
428 c->remote_id == -1)
429 return;
430 }
431
432 received_window_change_signal = 0;
433
434 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
435 return;
436
437 debug2("client_check_window_change: changed");
438
439 if (compat20) {
440 channel_request_start(session_ident, "window-change", 0);
441 packet_put_int(ws.ws_col);
442 packet_put_int(ws.ws_row);
443 packet_put_int(ws.ws_xpixel);
444 packet_put_int(ws.ws_ypixel);
445 packet_send();
446 } else {
447 packet_start(SSH_CMSG_WINDOW_SIZE);
448 packet_put_int(ws.ws_row);
449 packet_put_int(ws.ws_col);
450 packet_put_int(ws.ws_xpixel);
451 packet_put_int(ws.ws_ypixel);
452 packet_send();
453 }
454 }
455
456 static void
client_global_request_reply(int type,u_int32_t seq,void * ctxt)457 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
458 {
459 server_alive_timeouts = 0;
460 client_global_request_reply_fwd(type, seq, ctxt);
461 }
462
463 static void
server_alive_check(void)464 server_alive_check(void)
465 {
466 if (++server_alive_timeouts > options.server_alive_count_max) {
467 log("Timeout, server not responding.");
468 fatal_cleanup();
469 }
470 packet_start(SSH2_MSG_GLOBAL_REQUEST);
471 packet_put_cstring("keepalive@openssh.com");
472 packet_put_char(1); /* boolean: want reply */
473 packet_send();
474 }
475
476 /*
477 * Waits until the client can do something (some data becomes available on
478 * one of the file descriptors).
479 */
480
481 static void
client_wait_until_can_do_something(fd_set ** readsetp,fd_set ** writesetp,int * maxfdp,int * nallocp,int rekeying)482 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
483 int *maxfdp, int *nallocp, int rekeying)
484 {
485 struct timeval tv, *tvp;
486 int ret;
487
488 /* Add any selections by the channel mechanism. */
489 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
490
491 if (!compat20) {
492 /* Read from the connection, unless our buffers are full. */
493 if (buffer_len(&stdout_buffer) < buffer_high &&
494 buffer_len(&stderr_buffer) < buffer_high &&
495 channel_not_very_much_buffered_data())
496 FD_SET(connection_in, *readsetp);
497 /*
498 * Read from stdin, unless we have seen EOF or have very much
499 * buffered data to send to the server.
500 */
501 if (!stdin_eof && packet_not_very_much_data_to_write())
502 FD_SET(fileno(stdin), *readsetp);
503
504 /* Select stdout/stderr if have data in buffer. */
505 if (buffer_len(&stdout_buffer) > 0)
506 FD_SET(fileno(stdout), *writesetp);
507 if (buffer_len(&stderr_buffer) > 0)
508 FD_SET(fileno(stderr), *writesetp);
509 } else {
510 /* channel_prepare_select could have closed the last channel */
511 if (session_closed && !channel_still_open() &&
512 !packet_have_data_to_write()) {
513 /* clear mask since we did not call select() */
514 memset(*readsetp, 0, *nallocp);
515 memset(*writesetp, 0, *nallocp);
516 return;
517 } else {
518 FD_SET(connection_in, *readsetp);
519 }
520 }
521
522 /* Select server connection if have data to write to the server. */
523 if (packet_have_data_to_write())
524 FD_SET(connection_out, *writesetp);
525
526 /*
527 * Wait for something to happen. This will suspend the process until
528 * some selected descriptor can be read, written, or has some other
529 * event pending.
530 */
531
532 if (options.server_alive_interval == 0 || !compat20)
533 tvp = NULL;
534 else {
535 tv.tv_sec = options.server_alive_interval;
536 tv.tv_usec = 0;
537 tvp = &tv;
538 }
539 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
540 if (ret < 0) {
541 char buf[100];
542
543 /*
544 * We have to clear the select masks, because we return.
545 * We have to return, because the mainloop checks for the flags
546 * set by the signal handlers.
547 */
548 memset(*readsetp, 0, *nallocp);
549 memset(*writesetp, 0, *nallocp);
550
551 if (errno == EINTR)
552 return;
553 /* Note: we might still have data in the buffers. */
554 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
555 buffer_append(&stderr_buffer, buf, strlen(buf));
556 quit_pending = 1;
557 } else if (ret == 0)
558 server_alive_check();
559 }
560
561 static void
client_suspend_self(Buffer * bin,Buffer * bout,Buffer * berr)562 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
563 {
564 struct winsize oldws, newws;
565
566 /* Flush stdout and stderr buffers. */
567 if (buffer_len(bout) > 0)
568 atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
569 if (buffer_len(berr) > 0)
570 atomicio(write, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
571
572 leave_raw_mode();
573
574 /*
575 * Free (and clear) the buffer to reduce the amount of data that gets
576 * written to swap.
577 */
578 buffer_free(bin);
579 buffer_free(bout);
580 buffer_free(berr);
581
582 /* Save old window size. */
583 ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
584
585 /* Send the suspend signal to the program itself. */
586 kill(getpid(), SIGTSTP);
587
588 /* Check if the window size has changed. */
589 if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
590 (oldws.ws_row != newws.ws_row ||
591 oldws.ws_col != newws.ws_col ||
592 oldws.ws_xpixel != newws.ws_xpixel ||
593 oldws.ws_ypixel != newws.ws_ypixel))
594 received_window_change_signal = 1;
595
596 /* OK, we have been continued by the user. Reinitialize buffers. */
597 buffer_init(bin);
598 buffer_init(bout);
599 buffer_init(berr);
600
601 enter_raw_mode();
602 }
603
604 static void
client_process_net_input(fd_set * readset)605 client_process_net_input(fd_set * readset)
606 {
607 int len;
608 char buf[8192];
609
610 /*
611 * Read input from the server, and add any such data to the buffer of
612 * the packet subsystem.
613 */
614 if (FD_ISSET(connection_in, readset)) {
615 /* Read as much as possible. */
616 len = read(connection_in, buf, sizeof(buf));
617 if (len == 0) {
618 /* Received EOF. The remote host has closed the connection. */
619 snprintf(buf, sizeof buf,
620 gettext("Connection to %.300s closed "
621 "by remote host.\n"),
622 host);
623 buffer_append(&stderr_buffer, buf, strlen(buf));
624 quit_pending = 1;
625 return;
626 }
627 /*
628 * There is a kernel bug on Solaris that causes select to
629 * sometimes wake up even though there is no data available.
630 */
631 if (len < 0 && (errno == EAGAIN || errno == EINTR))
632 len = 0;
633
634 if (len < 0) {
635 /* An error has encountered. Perhaps there is a network problem. */
636 snprintf(buf, sizeof buf,
637 gettext("Read from remote host "
638 "%.300s: %.100s\n"),
639 host, strerror(errno));
640 buffer_append(&stderr_buffer, buf, strlen(buf));
641 quit_pending = 1;
642 return;
643 }
644 packet_process_incoming(buf, len);
645 }
646 }
647
648 static void
process_cmdline(void)649 process_cmdline(void)
650 {
651 void (*handler)(int);
652 char *s, *cmd;
653 int delete = 0;
654 int local = 0;
655 Forward fwd;
656
657 memset(&fwd, 0, sizeof(fwd));
658
659 leave_raw_mode();
660 handler = signal(SIGINT, SIG_IGN);
661 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
662 if (s == NULL)
663 goto out;
664 while (isspace(*s))
665 s++;
666 if (*s == '-')
667 s++; /* Skip cmdline '-', if any */
668 if (*s == '\0')
669 goto out;
670
671 if (*s == 'h' || *s == 'H' || *s == '?') {
672 log("Commands:");
673 log(" -L[bind_address:]port:host:hostport "
674 "Request local forward");
675 log(" -R[bind_address:]port:host:hostport "
676 "Request remote forward");
677 log(" -KR[bind_address:]port "
678 "Cancel remote forward");
679 goto out;
680 }
681
682 if (*s == 'K') {
683 delete = 1;
684 s++;
685 }
686 if (*s != 'L' && *s != 'R') {
687 log("Invalid command.");
688 goto out;
689 }
690 if (*s == 'L')
691 local = 1;
692 if (local && delete) {
693 log("Not supported.");
694 goto out;
695 }
696 if ((!local || delete) && !compat20) {
697 log("Not supported for SSH protocol version 1.");
698 goto out;
699 }
700
701 while (isspace(*++s))
702 ;
703
704 if (delete) {
705 if (parse_forward(0, &fwd, s) == 0) {
706 log("Bad forwarding close port");
707 goto out;
708 }
709 channel_request_rforward_cancel(fwd.listen_host, fwd.listen_port);
710 } else {
711 if (parse_forward(1, &fwd, s) == 0) {
712 log("Bad forwarding specification.");
713 goto out;
714 }
715 if (local) {
716 if (channel_setup_local_fwd_listener(fwd.listen_host,
717 fwd.listen_port, fwd.connect_host,
718 fwd.connect_port, options.gateway_ports) < 0) {
719 log("Port forwarding failed.");
720 goto out;
721 }
722 } else {
723 if (channel_request_remote_forwarding(fwd.listen_host,
724 fwd.listen_port, fwd.connect_host,
725 fwd.connect_port) < 0) {
726 log("Port forwarding failed.");
727 goto out;
728 }
729 }
730
731 log("Forwarding port.");
732 }
733
734 out:
735 signal(SIGINT, handler);
736 enter_raw_mode();
737 if (cmd != NULL)
738 xfree(cmd);
739 if (fwd.listen_host != NULL)
740 xfree(fwd.listen_host);
741 if (fwd.connect_host != NULL)
742 xfree(fwd.connect_host);
743 }
744
745 /*
746 * If we are using the engine we must not fork until we do key reexchange. See
747 * PKCS#11 spec for more information on fork safety and packet.c for information
748 * about forking with the engine.
749 */
750 void
client_daemonize(void)751 client_daemonize(void)
752 {
753 if (compat20 == 1 && options.use_openssl_engine == 1) {
754 will_daemonize = 1;
755 debug("must rekey before daemonizing");
756 kex_send_kexinit(xxx_kex);
757 need_rekeying = 0;
758 }
759 else {
760 if (daemon(1, 1) < 0) {
761 fatal("daemon() failed: %.200s",
762 strerror(errno));
763 }
764 }
765 }
766
767 /* process the characters one by one */
768 static int
process_escapes(Buffer * bin,Buffer * bout,Buffer * berr,char * buf,int len)769 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
770 {
771 char string[1536];
772 int bytes = 0;
773 u_int i;
774 u_char ch;
775 char *s;
776
777 for (i = 0; i < len; i++) {
778 /* Get one character at a time. */
779 ch = buf[i];
780
781 if (escape_pending) {
782 /* We have previously seen an escape character. */
783 /* Clear the flag now. */
784 escape_pending = 0;
785
786 /* Process the escaped character. */
787 switch (ch) {
788 case '.':
789 /* Terminate the connection. */
790 snprintf(string, sizeof string, "%c.\r\n", escape_char);
791 buffer_append(berr, string, strlen(string));
792
793 quit_pending = 1;
794 return -1;
795
796 case 'Z' - 64:
797 /* Suspend the program. */
798 /* Print a message to that effect to the user. */
799 snprintf(string, sizeof string,
800 gettext("%c^Z [suspend ssh]\n"),
801 escape_char);
802 buffer_append(berr, string, strlen(string));
803
804 /* Restore terminal modes and suspend. */
805 client_suspend_self(bin, bout, berr);
806
807 /* We have been continued. */
808 continue;
809
810 case 'B':
811 if (compat20) {
812 snprintf(string, sizeof string,
813 gettext("%cB [sent break]\n"),
814 escape_char);
815 buffer_append(berr, string,
816 strlen(string));
817 channel_request_start(session_ident,
818 "break", 0);
819 packet_put_int(1000);
820 packet_send();
821 }
822 continue;
823
824 case 'R':
825 if (compat20) {
826 if (datafellows & SSH_BUG_NOREKEY)
827 log("Server does not support re-keying");
828 else
829 need_rekeying = 1;
830 }
831 continue;
832
833 case '&':
834 /*
835 * Detach the program (continue to serve connections,
836 * but put in background and no more new connections).
837 */
838 /* Restore tty modes. */
839 leave_raw_mode();
840
841 /* Stop listening for new connections. */
842 channel_stop_listening();
843
844 snprintf(string, sizeof string,
845 gettext("%c& [backgrounded]\n"),
846 escape_char);
847 buffer_append(berr, string, strlen(string));
848
849 client_daemonize();
850
851 /* The child continues serving connections. */
852 if (compat20) {
853 buffer_append(bin, "\004", 1);
854 /* fake EOF on stdin */
855 return -1;
856 } else if (!stdin_eof) {
857 /*
858 * Sending SSH_CMSG_EOF alone does not always appear
859 * to be enough. So we try to send an EOF character
860 * first.
861 */
862 packet_start(SSH_CMSG_STDIN_DATA);
863 packet_put_string("\004", 1);
864 packet_send();
865 /* Close stdin. */
866 stdin_eof = 1;
867 if (buffer_len(bin) == 0) {
868 packet_start(SSH_CMSG_EOF);
869 packet_send();
870 }
871 }
872 continue;
873
874 case '?':
875 snprintf(string, sizeof string, gettext(
876 "%c?\n\
877 Supported escape sequences:\n\
878 %c. - terminate connection\n\
879 %cB - send break (SSH protocol 2 only)\n\
880 %cC - open a command line\n\
881 %cR - Request rekey (SSH protocol 2 only)\n\
882 %c^Z - suspend ssh\n\
883 %c# - list forwarded connections\n\
884 %c& - background ssh (when waiting for connections to terminate)\n\
885 %c? - this message\n\
886 %c%c - send the escape character by typing it twice\n\
887 (Note that escapes are only recognized immediately after newline.)\n"),
888 escape_char, escape_char, escape_char, escape_char,
889 escape_char, escape_char, escape_char, escape_char,
890 escape_char, escape_char);
891 buffer_append(berr, string, strlen(string));
892 continue;
893
894 case '#':
895 snprintf(string, sizeof string, "%c#\r\n", escape_char);
896 buffer_append(berr, string, strlen(string));
897 s = channel_open_message();
898 buffer_append(berr, s, strlen(s));
899 xfree(s);
900 continue;
901
902 case 'C':
903 process_cmdline();
904 continue;
905
906 default:
907 if (ch != escape_char) {
908 buffer_put_char(bin, escape_char);
909 bytes++;
910 }
911 /* Escaped characters fall through here */
912 break;
913 }
914 } else {
915 /*
916 * The previous character was not an escape char. Check if this
917 * is an escape.
918 */
919 if (last_was_cr && ch == escape_char) {
920 /* It is. Set the flag and continue to next character. */
921 escape_pending = 1;
922 continue;
923 }
924 }
925
926 /*
927 * Normal character. Record whether it was a newline,
928 * and append it to the buffer.
929 */
930 last_was_cr = (ch == '\r' || ch == '\n');
931 buffer_put_char(bin, ch);
932 bytes++;
933 }
934 return bytes;
935 }
936
937 static void
client_process_input(fd_set * readset)938 client_process_input(fd_set * readset)
939 {
940 int len;
941 char buf[8192];
942
943 /* Read input from stdin. */
944 if (FD_ISSET(fileno(stdin), readset)) {
945 /* Read as much as possible. */
946 len = read(fileno(stdin), buf, sizeof(buf));
947 if (len < 0 && (errno == EAGAIN || errno == EINTR))
948 return; /* we'll try again later */
949 if (len <= 0) {
950 /*
951 * Received EOF or error. They are treated
952 * similarly, except that an error message is printed
953 * if it was an error condition.
954 */
955 if (len < 0) {
956 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
957 buffer_append(&stderr_buffer, buf, strlen(buf));
958 }
959 /* Mark that we have seen EOF. */
960 stdin_eof = 1;
961 /*
962 * Send an EOF message to the server unless there is
963 * data in the buffer. If there is data in the
964 * buffer, no message will be sent now. Code
965 * elsewhere will send the EOF when the buffer
966 * becomes empty if stdin_eof is set.
967 */
968 if (buffer_len(&stdin_buffer) == 0) {
969 packet_start(SSH_CMSG_EOF);
970 packet_send();
971 }
972 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
973 /*
974 * Normal successful read, and no escape character.
975 * Just append the data to buffer.
976 */
977 buffer_append(&stdin_buffer, buf, len);
978 } else {
979 /*
980 * Normal, successful read. But we have an escape character
981 * and have to process the characters one by one.
982 */
983 if (process_escapes(&stdin_buffer, &stdout_buffer,
984 &stderr_buffer, buf, len) == -1)
985 return;
986 }
987 }
988 }
989
990 static void
client_process_output(fd_set * writeset)991 client_process_output(fd_set * writeset)
992 {
993 int len;
994 char buf[100];
995
996 /* Write buffered output to stdout. */
997 if (FD_ISSET(fileno(stdout), writeset)) {
998 /* Write as much data as possible. */
999 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1000 buffer_len(&stdout_buffer));
1001 if (len <= 0) {
1002 if (errno == EINTR || errno == EAGAIN)
1003 len = 0;
1004 else {
1005 /*
1006 * An error or EOF was encountered. Put an
1007 * error message to stderr buffer.
1008 */
1009 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1010 buffer_append(&stderr_buffer, buf, strlen(buf));
1011 quit_pending = 1;
1012 return;
1013 }
1014 }
1015 /* Consume printed data from the buffer. */
1016 buffer_consume(&stdout_buffer, len);
1017 stdout_bytes += len;
1018 }
1019 /* Write buffered output to stderr. */
1020 if (FD_ISSET(fileno(stderr), writeset)) {
1021 /* Write as much data as possible. */
1022 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1023 buffer_len(&stderr_buffer));
1024 if (len <= 0) {
1025 if (errno == EINTR || errno == EAGAIN)
1026 len = 0;
1027 else {
1028 /* EOF or error, but can't even print error message. */
1029 quit_pending = 1;
1030 return;
1031 }
1032 }
1033 /* Consume printed characters from the buffer. */
1034 buffer_consume(&stderr_buffer, len);
1035 stderr_bytes += len;
1036 }
1037 }
1038
1039 /*
1040 * Get packets from the connection input buffer, and process them as long as
1041 * there are packets available.
1042 *
1043 * Any unknown packets received during the actual
1044 * session cause the session to terminate. This is
1045 * intended to make debugging easier since no
1046 * confirmations are sent. Any compatible protocol
1047 * extensions must be negotiated during the
1048 * preparatory phase.
1049 */
1050
1051 static void
client_process_buffered_input_packets(void)1052 client_process_buffered_input_packets(void)
1053 {
1054 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1055 }
1056
1057 /* scan buf[] for '~' before sending data to the peer */
1058
1059 static int
simple_escape_filter(Channel * c,char * buf,int len)1060 simple_escape_filter(Channel *c, char *buf, int len)
1061 {
1062 /* XXX we assume c->extended is writeable */
1063 return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1064 }
1065
1066 static void
client_channel_closed(int id,void * arg)1067 client_channel_closed(int id, void *arg)
1068 {
1069 if (id != session_ident)
1070 error("client_channel_closed: id %d != session_ident %d",
1071 id, session_ident);
1072 channel_cancel_cleanup(id);
1073 session_closed = 1;
1074 if (in_raw_mode())
1075 leave_raw_mode();
1076 }
1077
1078 /*
1079 * Implements the interactive session with the server. This is called after
1080 * the user has been authenticated, and a command has been started on the
1081 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1082 * used as an escape character for terminating or suspending the session.
1083 */
1084
1085 int
client_loop(int have_pty,int escape_char_arg,int ssh2_chan_id)1086 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1087 {
1088 fd_set *readset = NULL, *writeset = NULL;
1089 double start_time, total_time;
1090 int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
1091 char buf[100];
1092
1093 debug("Entering interactive session.");
1094
1095 start_time = get_current_time();
1096
1097 /* Initialize variables. */
1098 escape_pending = 0;
1099 last_was_cr = 1;
1100 exit_status = -1;
1101 stdin_eof = 0;
1102 buffer_high = 64 * 1024;
1103 connection_in = packet_get_connection_in();
1104 connection_out = packet_get_connection_out();
1105 max_fd = MAX(connection_in, connection_out);
1106
1107 if (!compat20) {
1108 /* enable nonblocking unless tty */
1109 if (!isatty(fileno(stdin)))
1110 set_nonblock(fileno(stdin));
1111 if (!isatty(fileno(stdout)))
1112 set_nonblock(fileno(stdout));
1113 if (!isatty(fileno(stderr)))
1114 set_nonblock(fileno(stderr));
1115 max_fd = MAX(max_fd, fileno(stdin));
1116 max_fd = MAX(max_fd, fileno(stdout));
1117 max_fd = MAX(max_fd, fileno(stderr));
1118 }
1119 stdin_bytes = 0;
1120 stdout_bytes = 0;
1121 stderr_bytes = 0;
1122 quit_pending = 0;
1123 escape_char = escape_char_arg;
1124
1125 /* Initialize buffers. */
1126 buffer_init(&stdin_buffer);
1127 buffer_init(&stdout_buffer);
1128 buffer_init(&stderr_buffer);
1129
1130 client_init_dispatch();
1131
1132 /*
1133 * Set signal handlers to restore non-blocking mode, but
1134 * don't overwrite SIG_IGN - matches behavious from rsh(1).
1135 */
1136 if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1137 signal(SIGINT, signal_handler);
1138 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1139 signal(SIGQUIT, signal_handler);
1140 if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1141 signal(SIGTERM, signal_handler);
1142 if (have_pty)
1143 signal(SIGWINCH, window_change_handler);
1144
1145 if (have_pty)
1146 enter_raw_mode();
1147
1148 if (compat20) {
1149 session_ident = ssh2_chan_id;
1150 if (escape_char != SSH_ESCAPECHAR_NONE)
1151 channel_register_filter(session_ident,
1152 simple_escape_filter);
1153 if (session_ident != -1)
1154 channel_register_cleanup(session_ident,
1155 client_channel_closed);
1156 } else {
1157 /* Check if we should immediately send eof on stdin. */
1158 client_check_initial_eof_on_stdin();
1159 }
1160
1161 /* Main loop of the client for the interactive session mode. */
1162 while (!quit_pending) {
1163
1164 /* Process buffered packets sent by the server. */
1165 client_process_buffered_input_packets();
1166
1167 if (compat20 && session_closed && !channel_still_open())
1168 break;
1169
1170 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1171
1172 if (rekeying) {
1173 debug("rekeying in progress");
1174 } else {
1175 /*
1176 * Make packets of buffered stdin data, and buffer
1177 * them for sending to the server.
1178 */
1179 if (!compat20)
1180 client_make_packets_from_stdin_data();
1181
1182 /*
1183 * Make packets from buffered channel data, and
1184 * enqueue them for sending to the server.
1185 */
1186 if (packet_not_very_much_data_to_write())
1187 channel_output_poll();
1188
1189 /*
1190 * Check if the window size has changed, and buffer a
1191 * message about it to the server if so.
1192 */
1193 client_check_window_change();
1194
1195 if (quit_pending)
1196 break;
1197 }
1198 /*
1199 * Wait until we have something to do (something becomes
1200 * available on one of the descriptors).
1201 */
1202 max_fd2 = max_fd;
1203 client_wait_until_can_do_something(&readset, &writeset,
1204 &max_fd2, &nalloc, rekeying);
1205
1206 if (quit_pending)
1207 break;
1208
1209 /* Do channel operations unless rekeying in progress. */
1210 if (!rekeying) {
1211 channel_after_select(readset, writeset);
1212 if (need_rekeying || packet_need_rekeying()) {
1213 debug("rekey limit reached, need rekeying");
1214 kex_send_kexinit(xxx_kex);
1215 need_rekeying = 0;
1216 }
1217 }
1218
1219 /* Buffer input from the connection. */
1220 client_process_net_input(readset);
1221
1222 if (quit_pending)
1223 break;
1224
1225 if (!compat20) {
1226 /* Buffer data from stdin */
1227 client_process_input(readset);
1228 /*
1229 * Process output to stdout and stderr. Output to
1230 * the connection is processed elsewhere (above).
1231 */
1232 client_process_output(writeset);
1233 }
1234
1235 /* Send as much buffered packet data as possible to the sender. */
1236 if (FD_ISSET(connection_out, writeset))
1237 packet_write_poll();
1238 }
1239 if (readset)
1240 xfree(readset);
1241 if (writeset)
1242 xfree(writeset);
1243
1244 /* Terminate the session. */
1245
1246 /* Stop watching for window change. */
1247 if (have_pty)
1248 signal(SIGWINCH, SIG_DFL);
1249
1250 channel_free_all();
1251
1252 if (have_pty)
1253 leave_raw_mode();
1254
1255 /* restore blocking io */
1256 if (!isatty(fileno(stdin)))
1257 unset_nonblock(fileno(stdin));
1258 if (!isatty(fileno(stdout)))
1259 unset_nonblock(fileno(stdout));
1260 if (!isatty(fileno(stderr)))
1261 unset_nonblock(fileno(stderr));
1262
1263 if (received_signal) {
1264 if (in_non_blocking_mode) /* XXX */
1265 leave_non_blocking();
1266 fatal("Killed by signal %d.", (int) received_signal);
1267 }
1268
1269 /*
1270 * In interactive mode (with pseudo tty) display a message indicating
1271 * that the connection has been closed.
1272 */
1273 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1274 snprintf(buf, sizeof buf,
1275 gettext("Connection to %.64s closed.\n"),
1276 host);
1277 buffer_append(&stderr_buffer, buf, strlen(buf));
1278 }
1279
1280 /* Output any buffered data for stdout. */
1281 while (buffer_len(&stdout_buffer) > 0) {
1282 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1283 buffer_len(&stdout_buffer));
1284 if (len <= 0) {
1285 error("Write failed flushing stdout buffer.");
1286 break;
1287 }
1288 buffer_consume(&stdout_buffer, len);
1289 stdout_bytes += len;
1290 }
1291
1292 /* Output any buffered data for stderr. */
1293 while (buffer_len(&stderr_buffer) > 0) {
1294 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1295 buffer_len(&stderr_buffer));
1296 if (len <= 0) {
1297 error("Write failed flushing stderr buffer.");
1298 break;
1299 }
1300 buffer_consume(&stderr_buffer, len);
1301 stderr_bytes += len;
1302 }
1303
1304 /* Clear and free any buffers. */
1305 memset(buf, 0, sizeof(buf));
1306 buffer_free(&stdin_buffer);
1307 buffer_free(&stdout_buffer);
1308 buffer_free(&stderr_buffer);
1309
1310 /* Report bytes transferred, and transfer rates. */
1311 total_time = get_current_time() - start_time;
1312 debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1313 stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1314 if (total_time > 0)
1315 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1316 stdin_bytes / total_time, stdout_bytes / total_time,
1317 stderr_bytes / total_time);
1318
1319 /* Return the exit status of the program. */
1320 debug("Exit status %d", exit_status);
1321 return exit_status;
1322 }
1323
1324 /*********/
1325
1326 static void
client_input_stdout_data(int type,u_int32_t seq,void * ctxt)1327 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1328 {
1329 u_int data_len;
1330 char *data = packet_get_string(&data_len);
1331 packet_check_eom();
1332 buffer_append(&stdout_buffer, data, data_len);
1333 memset(data, 0, data_len);
1334 xfree(data);
1335 }
1336 static void
client_input_stderr_data(int type,u_int32_t seq,void * ctxt)1337 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1338 {
1339 u_int data_len;
1340 char *data = packet_get_string(&data_len);
1341 packet_check_eom();
1342 buffer_append(&stderr_buffer, data, data_len);
1343 memset(data, 0, data_len);
1344 xfree(data);
1345 }
1346 static void
client_input_exit_status(int type,u_int32_t seq,void * ctxt)1347 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1348 {
1349 exit_status = packet_get_int();
1350 packet_check_eom();
1351 /* Acknowledge the exit. */
1352 packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1353 packet_send();
1354 /*
1355 * Must wait for packet to be sent since we are
1356 * exiting the loop.
1357 */
1358 packet_write_wait();
1359 /* Flag that we want to exit. */
1360 quit_pending = 1;
1361 }
1362
1363 static Channel *
client_request_forwarded_tcpip(const char * request_type,int rchan)1364 client_request_forwarded_tcpip(const char *request_type, int rchan)
1365 {
1366 Channel *c = NULL;
1367 char *listen_address, *originator_address;
1368 int listen_port, originator_port;
1369 int sock;
1370
1371 /* Get rest of the packet */
1372 listen_address = packet_get_string(NULL);
1373 listen_port = packet_get_int();
1374 originator_address = packet_get_string(NULL);
1375 originator_port = packet_get_int();
1376 packet_check_eom();
1377
1378 debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1379 listen_address, listen_port, originator_address, originator_port);
1380
1381 sock = channel_connect_by_listen_address(listen_port);
1382 if (sock < 0) {
1383 xfree(originator_address);
1384 xfree(listen_address);
1385 return NULL;
1386 }
1387 c = channel_new("forwarded-tcpip",
1388 SSH_CHANNEL_CONNECTING, sock, sock, -1,
1389 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1390 xstrdup(originator_address), 1);
1391 xfree(originator_address);
1392 xfree(listen_address);
1393 return c;
1394 }
1395
1396 static Channel *
client_request_x11(const char * request_type,int rchan)1397 client_request_x11(const char *request_type, int rchan)
1398 {
1399 Channel *c = NULL;
1400 char *originator;
1401 int originator_port;
1402 int sock;
1403
1404 if (!options.forward_x11) {
1405 error("Warning: ssh server tried X11 forwarding.");
1406 error("Warning: this is probably a break in attempt by a malicious server.");
1407 return NULL;
1408 }
1409 originator = packet_get_string(NULL);
1410 if (datafellows & SSH_BUG_X11FWD) {
1411 debug2("buggy server: x11 request w/o originator_port");
1412 originator_port = 0;
1413 } else {
1414 originator_port = packet_get_int();
1415 }
1416 packet_check_eom();
1417 /* XXX check permission */
1418 debug("client_request_x11: request from %s %d", originator,
1419 originator_port);
1420 xfree(originator);
1421 sock = x11_connect_display();
1422 if (sock < 0)
1423 return NULL;
1424 c = channel_new("x11",
1425 SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1426 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0,
1427 xstrdup("x11"), 1);
1428 c->force_drain = 1;
1429 return c;
1430 }
1431
1432 static Channel *
client_request_agent(const char * request_type,int rchan)1433 client_request_agent(const char *request_type, int rchan)
1434 {
1435 Channel *c = NULL;
1436 int sock;
1437
1438 if (!options.forward_agent) {
1439 error("Warning: ssh server tried agent forwarding.");
1440 error("Warning: this is probably a break in attempt by a malicious server.");
1441 return NULL;
1442 }
1443 sock = ssh_get_authentication_socket();
1444 if (sock < 0)
1445 return NULL;
1446 c = channel_new("authentication agent connection",
1447 SSH_CHANNEL_OPEN, sock, sock, -1,
1448 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1449 xstrdup("authentication agent connection"), 1);
1450 c->force_drain = 1;
1451 return c;
1452 }
1453
1454 /* XXXX move to generic input handler */
1455 static void
client_input_channel_open(int type,u_int32_t seq,void * ctxt)1456 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1457 {
1458 Channel *c = NULL;
1459 char *ctype;
1460 int rchan;
1461 u_int rmaxpack, rwindow, len;
1462
1463 ctype = packet_get_string(&len);
1464 rchan = packet_get_int();
1465 rwindow = packet_get_int();
1466 rmaxpack = packet_get_int();
1467
1468 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1469 ctype, rchan, rwindow, rmaxpack);
1470
1471 if (strcmp(ctype, "forwarded-tcpip") == 0) {
1472 c = client_request_forwarded_tcpip(ctype, rchan);
1473 } else if (strcmp(ctype, "x11") == 0) {
1474 c = client_request_x11(ctype, rchan);
1475 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1476 c = client_request_agent(ctype, rchan);
1477 }
1478 /* XXX duplicate : */
1479 if (c != NULL) {
1480 debug("confirm %s", ctype);
1481 c->remote_id = rchan;
1482 c->remote_window = rwindow;
1483 c->remote_maxpacket = rmaxpack;
1484 if (c->type != SSH_CHANNEL_CONNECTING) {
1485 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1486 packet_put_int(c->remote_id);
1487 packet_put_int(c->self);
1488 packet_put_int(c->local_window);
1489 packet_put_int(c->local_maxpacket);
1490 packet_send();
1491 }
1492 } else {
1493 debug("failure %s", ctype);
1494 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1495 packet_put_int(rchan);
1496 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1497 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1498 packet_put_utf8_cstring("open failed");
1499 packet_put_cstring("");
1500 }
1501 packet_send();
1502 }
1503 xfree(ctype);
1504 }
1505
1506 static void
client_input_channel_req(int type,u_int32_t seq,void * ctxt)1507 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1508 {
1509 Channel *c = NULL;
1510 int id, reply, success = 0;
1511 char *rtype;
1512
1513 id = packet_get_int();
1514 rtype = packet_get_string(NULL);
1515 reply = packet_get_char();
1516
1517 debug("client_input_channel_req: channel %d rtype %s reply %d",
1518 id, rtype, reply);
1519
1520 if (session_ident == -1) {
1521 error("client_input_channel_req: no channel %d", session_ident);
1522 } else if (id != session_ident) {
1523 error("client_input_channel_req: channel %d: wrong channel: %d",
1524 session_ident, id);
1525 }
1526 c = channel_lookup(id);
1527 if (c == NULL) {
1528 error("client_input_channel_req: channel %d: unknown channel", id);
1529 } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1530 packet_check_eom();
1531 chan_rcvd_eow(c);
1532 } else if (strcmp(rtype, "exit-status") == 0) {
1533 success = 1;
1534 exit_status = packet_get_int();
1535 packet_check_eom();
1536 }
1537 if (reply) {
1538 packet_start(success ?
1539 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1540 packet_put_int(c->remote_id);
1541 packet_send();
1542 }
1543 xfree(rtype);
1544 }
1545
1546 static void
client_input_global_request(int type,u_int32_t seq,void * ctxt)1547 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1548 {
1549 char *rtype;
1550 int want_reply;
1551 int success = 0;
1552
1553 rtype = packet_get_string(NULL);
1554 want_reply = packet_get_char();
1555 debug("client_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1556 if (want_reply) {
1557 packet_start(success ?
1558 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1559 packet_send();
1560 packet_write_wait();
1561 }
1562 xfree(rtype);
1563 }
1564
1565 static void
client_init_dispatch_20(void)1566 client_init_dispatch_20(void)
1567 {
1568 dispatch_init(&dispatch_protocol_error);
1569
1570 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1571 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1572 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1573 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1574 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1575 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1576 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1577 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1578 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1579 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1580
1581 /* rekeying */
1582 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1583
1584 /* global request reply messages */
1585 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1586 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1587 }
1588
1589 static void
client_init_dispatch_13(void)1590 client_init_dispatch_13(void)
1591 {
1592 dispatch_init(NULL);
1593 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1594 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1595 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1596 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1597 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1598 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1599 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1600 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1601 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1602
1603 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1604 &auth_input_open_request : &deny_input_open);
1605 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1606 &x11_input_open : &deny_input_open);
1607 }
1608
1609 static void
client_init_dispatch_15(void)1610 client_init_dispatch_15(void)
1611 {
1612 client_init_dispatch_13();
1613 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1614 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1615 }
1616
1617 static void
client_init_dispatch(void)1618 client_init_dispatch(void)
1619 {
1620 if (compat20)
1621 client_init_dispatch_20();
1622 else if (compat13)
1623 client_init_dispatch_13();
1624 else
1625 client_init_dispatch_15();
1626 }
1627